Conventionally, a technique for performing image correction more appropriate for people having decreased visual characteristics (also referred to as low vision) compared to people having normal visual characteristics has been under consideration. The causal factors of the decreased visual characteristics include, for example, an age-related cataract, diabetic retinopathy, and age-related macular degeneration.
For example, one known technique includes a technique which causes a luminance signal level to non-linearly change according to an average luminance level of an image, for forming a bright and clear picture in image reproduction appropriate for the visual characteristics of elderly people (for example, Patent Literature (PLT) 1).
PLT 1 describes a technique which uses, as gain characteristics, a plurality of S-shaped curves having different shapes according to an average luminance when correcting a luminance gradation, and thereby expanding the luminance gradation to a greater degree in a middle luminance range and compressing the luminance gradations to a greater degree in a low luminance range and a high luminance range as the average luminance decreases.
Another known technique is, for example, a technique which increases the luminance of a specific color for a viewer with cataract (for example, PLT 2).
PLT 2 describes a technique which performs correction of increasing luminance of blue or increasing luminance of blue and green, according to the level of progress of cataract of a viewer.